software.amazon.awssdk.services.dynamodb.paginators

Class ScanPublisher

java.lang.Object

software.amazon.awssdk.services.dynamodb.paginators.ScanPublisher

All Implemented Interfaces:

org.reactivestreams.Publisher<ScanResponse>, SdkPublisher<ScanResponse>

@Generated(value="software.amazon.awssdk:codegen")
public class ScanPublisher
extends Object
implements SdkPublisher<ScanResponse>

Represents the output for the DynamoDbAsyncClient.scanPaginator(software.amazon.awssdk.services.dynamodb.model.ScanRequest) operation which is a paginated operation. This class is a type of Publisher which can be used to provide a sequence of ScanResponse response pages as per demand from the subscriber.

When the operation is called, an instance of this class is returned. At this point, no service calls are made yet and so there is no guarantee that the request is valid. If there are errors in your request, you will see the failures only after you start streaming the data. The subscribe method should be called as a request to start streaming data. For more info, see Publisher.subscribe(org.reactivestreams.Subscriber). Each call to the subscribe method will result in a new Subscription i.e., a new contract to stream data from the starting request.

The following are few ways to use the response class:

1) Using the subscribe helper method

 
 software.amazon.awssdk.services.dynamodb.paginators.ScanPublisher publisher = client.scanPaginator(request);
 CompletableFuture<Void> future = publisher.subscribe(res -> { // Do something with the response });
 future.get();
 
 

2) Using a custom subscriber

 
 software.amazon.awssdk.services.dynamodb.paginators.ScanPublisher publisher = client.scanPaginator(request);
 publisher.subscribe(new Subscriber<software.amazon.awssdk.services.dynamodb.model.ScanResponse>() {
 
 public void onSubscribe(org.reactivestreams.Subscriber subscription) { //... };
 
 
 public void onNext(software.amazon.awssdk.services.dynamodb.model.ScanResponse response) { //... };
 });
 

As the response is a publisher, it can work well with third party reactive streams implementations like RxJava2.

Please notice that the configuration of Limit won't limit the number of results you get with the paginator. It only limits the number of results in each page.

Note: If you prefer to have control on service calls, use the #scan(software.amazon.awssdk.services.dynamodb.model.ScanRequest) operation.

Constructor Summary

Constructors

Constructor and Description
ScanPublisher(DynamoDbAsyncClient client, ScanRequest firstRequest)

Method Summary

Modifier and Type	Method and Description
SdkPublisher<Map<String,AttributeValue>>	items() Returns a publisher that can be used to get a stream of data.
void	subscribe(org.reactivestreams.Subscriber<? super ScanResponse> subscriber)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface software.amazon.awssdk.core.async.SdkPublisher

adapt, buffer, filter, filter, flatMapIterable, limit, map, subscribe

Constructor Detail

ScanPublisher

public ScanPublisher(DynamoDbAsyncClient client,
                     ScanRequest firstRequest)

Method Detail

subscribe

public void subscribe(org.reactivestreams.Subscriber<? super ScanResponse> subscriber)

Specified by:

subscribe in interface org.reactivestreams.Publisher<ScanResponse>

items

public final SdkPublisher<Map<String,AttributeValue>> items()

Returns a publisher that can be used to get a stream of data. You need to subscribe to the publisher to request the stream of data. The publisher has a helper forEach method that takes in a Consumer and then applies that consumer to each response returned by the service.